The motor temp during touch method works good for determining what the motors may need. Unless flying with the GPS turned off it's doubtful they would become too hot. Flying high speed and pulling a lot more amps with GPS off might well generate more heat at the motors and ECSs, requiring some cool down time. Tossing a white towel over the top of the H when sitting in the sun while not being used might not be a bad idea to help keep inside temps down a little bit. We've been doing that with RC airplanes for years to keep the electronics cooler. Lifting it away from the hot ground where it collects a lot of reflected heat is also not a bad idea. If it's 100* in the air the ground is probably 20*+ more than that if it's bare dirt, concrete, or asphalt.
I just did a 3 day shoot that kept batteries changing out back to back in 95* heat with no problems at the H side of things but just after completion the ST-16 started complaining and required re-calibrating all the controls along with the button and switch functions. I don't know that was from getting used heavily in the hot sun, sitting too long in a hot car, or just one of those things. Interestingly, communication of the problem was provided by the H, not the controller.